Just a note on size and efficiency. Higher power gold and platinum PS will use less power out of the wall than smaller PS's that may be adequate in wattage output. A 1200 watt gold PS will use less power at the wall putting out 500 watts than a 550 watt 80+, by a fairly significant margin, because PS's are most efficient with about 40 to 60% output of their full rating. Read the reviews and PS articles. I ended up with a Corsair AX 750 gold, replacing a 7 year old Thermaltake 600watt 80+ and I am using 30 less watts total at the wall. Ripple, current output, single or multiple 12v rails, modular cables and fan noise all have to be considered. Non-gaming, my fan never turns on, with my older PS, the fan was always on and it was always hot! Bigger, higher quality PS's can pay for the difference in price over time in power bills, not to mention it gives you more room for upgrades later.